Impact of Two-Body Currents on Semi-Exclusive Lepton-Nucleus Reactions

TL;DR

This paper advances the spectral-function formalism to better model two-nucleon knockout processes in lepton-nucleus reactions, emphasizing improved current operator treatment and nucleon correlation modeling, validated against experimental data.

Contribution

It introduces a generalized formalism incorporating detailed current operators and nucleon correlations, enhancing the accuracy of semi-exclusive lepton-nucleus reaction modeling.

Findings

Improved agreement with experimental scattering data.

Enhanced understanding of nuclear dynamics in reaction mechanisms.

Significant impact of correlations on electroweak observables.

Abstract

We generalize the spectral-function formalism to describe two-nucleon knockout processes in exclusive kinematics. Significant improvements are introduced both in the treatment of the current operators entering the $\Delta$-current contribution and in the modeling of correlations between the two struck nucleons, including a consistent treatment of isospin dependence and the explicit incorporation of angular correlations. The framework is validated through comparisons with relativistic Fermi-gas calculations and with semi-exclusive electron-nucleus scattering data. Our results demonstrate that an accurate description of nuclear dynamics plays a crucial role in modeling this reaction mechanism. We further present a study of selected electroweak observables relevant to neutrino-scattering experiments.